Door-spuing



UNITE SAMUEL SAWYER, OF BOSTON, MASSACHUSETTS.

DOOR-SPRING.

Specification of Letters Patent No. 1,938, dated January 21, 1841.

T 0 all 'whom t may concern Be it known that I, SAMUEL SAwYER, ofBoston, in the county of Suffolk and State of Massachusetts, haveinvented a new, useful, and Improved Door-Spring, and that the followingis a full and exact description of the same, which taken in connectionwith the accompanying drawings hereinafter referred to compose myspecification, setting forth and exhibiting the principles ofconstruction of my improvement by which it may be distinguished fromother inventions of a like character, and such parts or combinationstherein I claim and for which I solicit an exclusive property to besecured to me for fourteen years by Letters Patent.

Figure l represents a top View, Fig. 2, a front elevation, and Fig. 3, atransverse horizontal section of my door spring.l

The peculiar object of the same, is, by the arrangement of the severalparts, to so apply the expansive force of the spring to the door, thatit shall be exerted thereon with an increased force to close the same,as the door advances forward, from a position open at an angle of ninetydegrees or more, to its situation when closed. Other door springsgenerally act on a principle exactly the reverse of the above, andusually fail, especially after being some time in use), to shut the doorwith a force sufficient to close the latch.

My spring, besides possessing the above advantages, has the merit ofsimplicity and cheapness, two very essential requisites. It isconstructed as follows: A, Figs. 2, 3, represents a spring formed of athin plate of steel or other suitable material, coiled around into aspiral shape, and having one of its ends, viz. a?, (see Fig. 3) bent toabout a right angle, and confined to the door N, by being inserted in agroove C cut in the rear of the plate B, which is screwed'to the door attop and supports the spring during its operations. The other end of thespring, or a, is also similarly bent at right angles and inserted in achannel or groove b formed lengthwise in the surface of an uprightturning pin C, seen in section in Fig. 3, and by dotted lines in Fig. 2.There may be several grooves or channels likev b, scored or cut in theturning pin or shaft so as to adjust the power of the spring byinserting the end of the same in either at pleasure. The spring A isplaced between two shelves D, E, projecting perpendicularly from theplate B, and rests on the lower shelf D as seen in Fig. 2. The turningpin, or shaft C, passes through the shelf E and has a shoulder e formedon its lower end, by which it is supported on the upper surface of theshelf D. The pin also passes through the shelf D and is secured fromrising upward by a pin F, inserted in a hole through the foot of thesame, just below the lower face of the shelf D, or by any other suitablecontrivance. An arm G, Figs. l and 2, is attached to the top of the pinC projecting therefrom at right angles. The other extremity of lthe armG is jointed to a bar H, the end of the latter resting on the top ofthat of the former and being held down on the same, by and freelyturning on a pin I. sThe other end of the bar H is inserted between twoears or projections e, f from a plate L (secured to the door frame Mabove the plate B and somewhat aside, or so that the arm G and barbflshall make an acute angle with each other when the door is closed asrepresented in Figs. 1, and 2), and turns on a pin K passing through theprojections and the said bar.

The above constitutes the whole of the apparatus, the operation of whichis as follows. Fig. 1, shows the position of the parts when the door Nis closed; the ydotted lines therein also representing the door open atan angle of ninety degrees. Now, as the door is opened the pin I, in theend of the arm G, bears laterally against the end of the bar H andpresses the same around on the pin K, into the position denoted by thedotted lines in Fig. 1, the arm G at the same time, turning about theupright pin or shaft C and drawing up or contracting the spring A. Whenthe force which opens the door is removed, the expansion of the spring Aacting on the shaft C and arm G, will close the same with a forcegradually increasing as the door proceeds toward the frame. Although thepower of the spring decreases as it becomes more expanded-yet the peculiar arrangement of the arm Gl and bar H will cause the action orpressure thereof tending to close the door, to be continually increasingthereon as herein before mentioned.

Having thus described my improved door spring, I shall claim,

Constructing the same with a turning shaft or pin C connected to, andoperated by a spring A, applied to the door in manseription of my saidinvention and improvel0 ment I have hereto set my signature this twentyeighth day of November in the year of our Lord, eighteen hundred andforty.

SAMUEL SAW YER.

Witnesses:

R. H EDDY, EZRA LINCOLN, J r.

